Matamata Greenhouses using energy efficiency to make growing gains
Trialling an innovative technology to dehumidify greenhouses has proved fruitful for Matamata-based Southern Belle Orchard, helping them save on energy costs, cut emissions and increase productivity – with assistance from the Energy Efficiency and Conservation Authority (EECA).
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Southern Belle Orchard in Matamata, owned by scientist-turned-farmer Frans de Jong, grows capsicums and chillies inside large greenhouses.
Greenhouses, like those at Southern Belle Orchard, have vents to the outside air to help mitigate the build-up of condensation from transpiring plants – however opening these vents means a significant loss of energy used to heat the glasshouse. Greenhouse farmers then have to compromise between optimal temperature and optimal humidity conditions.
Capsicums, like other vegetable crops, are highly susceptible to humidity related diseases. High humidity in greenhouses can also cause lower rates of pollination, ruin fruit due to water pressure imbalance, and reduce yield.
Frans began to look around for a solution to this common problem. He worked with Dinesh Chand, technology innovation manager at EECA, to access co-funding support from EECA’s technology demonstration fund to invest in state-of-the-art dehumidifiers from Israel-based company DryGair.
The units installed at Southern Belle Orchard by DryGair extract 45 litres of water per hour from air in the greenhouse, and then re-circulate that air to create uniform air flow across planting rows. The extracted water is also re-used for irrigation, carrying nutrients back to the plant roots.
Since the technology was installed in early March, de Jong has been tweaking the DryGair units in order to get optimum dehumidification using the least amount of energy. The benefits of dehumidification are already apparent, both in energy savings and plant productivity.
“The plants are much happier because they aren’t getting fungal problems. We also see increased growth from plants because with less water in the air, plants can transpire properly. This means they will take up water from the ground, and with it they take up nutrients they need to grow. That means more productive plants, which means more fruit.”
Frans estimates the units will save around $8000 a year, and will halve the farm’s yearly fuel consumption of 50,000 litres, between his two greenhouses.
“With this technology you’re able to work in a closed space, you don’t have to bring in cold air and then reheat it with the use of fossil fuels to maintain low humidity levels. All of the warm air that you’ve collected during the day is able to stay inside of the greenhouse, and the humidity is still removed. This yields huge energy efficiency benefits – we see that on average, the energy savings of these units are around 50 percent.”
Chand was glad to see the preliminary savings from installing the technology, and encourages other businesses to reach out to EECA to discuss investing in energy efficient equipment fit for their requirements.
“The horticultural sector is a significant energy user in New Zealand, and it’s great to see innovative technologies deployed to support this vital industry. This dehumidifying technology is applicable to anyone working with greenhouses across the country who wishes to see the benefits of significant energy and cost savings.”
Southern Belle Orchard was crowned the Supreme Winner in the 2015 Waikato Farm Environment Awards, and de Jong is determined to take further measures to reduce the use of fossil fuels.
“As well as the cost savings to the business, it’s also great to be able to operate more sustainably. It’s really important to me personally to lower our impact on the environment. In terms of other sustainable projects, we are looking to power our greenhouses with solar panels – it seems like a no brainer to move towards becoming more energy efficient, in terms of cost savings and lowering carbon emissions. ”
Find more information about EECA’s technology demonstration funding available to businesses at the link below.